Recent legislative and regulatory changes have been made to spur a more open service provider environment in the telecommunications industry. Subscription to local telephone service, open to competition, no longer will be limited to incumbent local exchange carriers (ILECs) such as the regional Bell Operating companies.
One aspect of this open environment policy pertains to competing local exchange carriers (CLECs) that are facility based, e.g., those competing carriers that have their own independent switching facilities. These facilities must be integrated into the public switched telephone network (PSTN) in a seamless manner from the user's perspective. The concept of user telephone number portability is basic to this end. In general, number portability refers to the ability of end users to retain their geographic or non-geographic telephone number when they change their service provider, their location, or their service. A wide application of number portability, for example, would permit a user to keep the same telephone number at the same or different location, while terminating service from one provider in favor of a new service provider, and moving from plain old telephone service (POTS) to integrated digital services network (ISDN). The Federal Communications Commission has proposed standards for local number portability (LNP) that relates to the ability of a telephone service subscriber to select or change the selection of a carrier for providing that customer's local telephone service, while still maintaining the subscriber's telephone number at the same customer premises.
FIG. 1 is a simplified diagram exemplifying a public switched telephone network in which switching facilities of both an incumbent local exchange carrier and a competing local exchange carrier are available for direct loop connection to the subscriber. A customer having telephone or like communication equipment at station 11 may obtain local exchange telephone service from either an original ILEC served by its end office 13, or a CLEC having an end office 15. The CLEC end office 15 may connect through trunk circuits to each ILEC end office in the area of service or to a trunk connection with an access tandem 23. Although not shown, the CLEC end office 15 also would connect into the common channel interoffice signaling network, at least for the exchange of call-setup related signaling messages. In the illustrated example, the subscriber at station 11, who originally received service through the ILEC has now selected the CLEC in replacement thereof for local service. Accordingly, the station 11 is shown connected to the CLEC end office 15, the previous subscriber loop connection to ILEC end office 13 having been disabled. Signaling Transfer Point (STP) 19 and Integrated Service Control Point (ISCP) are components of the known Advanced Intelligent Network (AIN) within which at least part of the common channeling signaling network is included. Various approaches have been undertaken to provide number portability for an arrangement such as this example that are not directly relevant to the present invention.
Another aspect of the open environment policy is embodied in a requirement that an ILEC unbundle certain network elements and services and offer use of those elements and services to other carriers, CLECs who may have remotely located switches but do not have facilities for direct local connection, for resale to end users. The ILEC, for example, must make available for sale to another carrier an unbundled port on an end office switch. The other carrier can then become a competing local exchange carrier by reselling services of the switch to end users having local loops that connect to the end office switch. The statutory and regulatory changes also require that customized routing be available for both unbundled switching and for resale. Customized routing is the term used in the regulations for routing calls made in the ILEC switch to locations other than normal routing locations.
Telephone service capability, of course, has extended beyond the POTS voice and ISDN communication of decades ago. With the advent of digital communications, the variety of telecommunication services and number of specialized service providers have increased at a remarkable pace. The availability of information in the form of data from various sources has spurred large public demand for broadband data transfer that challenges the capabilities of communication delivery systems. The number of information sources publicly and interactively available via the internet to personal computers, as well as private data network sources, continues to proliferate. Full motion video programming and source material also has rapidly progressed from early television broadcasting and cable distribution networks to a wide variety of distribution arrangements, including direct broadcast satellite television. The number of full motion video sources has expanded in response to increased usage and user demand for a greater range of subject matter content.
To meet user requirements, more robust broadband networks have evolved. For example, U.S. Pat. No. 5,247,347 to Litteral et al., discloses a digital video distribution network providing subscribers with access to multiple Video On Demand service providers through the public switched telephone network. The subscriber may transmit ordering information via the public switched telephone network to the independent video information providers. Video programming may be accessed and transmitted to the subscriber directly from a video information provider (VIP) or through a video buffer located at a central office (CO) serving the subscriber. Connectivity between the central office and the subscriber for transmission of video data is provided by an asymmetrical digital subscriber line (ADSL) system. ADSL, which has been standardized by ANSI as T1.413, uses existing unshielded twisted pair copper wires from the telephone company central office to the subscriber's premises. Equipment at the central office and the subscriber's premises permits transfer of more high speed digital information signals to the subscriber than in the reverse direction. The standard is directed to carrying video (broadband) to the home while returning control signals from the home at 16 Kbps.
In the Litteral et al. patent, ADSL interface units at the central office multiplex digital video information with voice information to be transmitted to the subscriber and support two-way transmission between the subscriber's line and the X.25 packet data network of one or more control channels. A subscriber may use either a standard telephone instrument over the public switched telephone network or a dedicated control device over an ISDN packet network to order video programming. The request is transmitted to a designated video information provider and digital transmission connectivity is established between the video information provider and the central office serving the subscriber. Connectivity between the central office and subscriber is provided by asymmetrical digital subscriber line interface units over a local loop. The interface units frequency multiplex digital video information with voice information to the subscriber and support transmission of a reverse transmission channel from the subscriber to the central office for transmission on the ISDN packet data network back to the video information provider. The interfaces also allow baseband signaling and audio between the central office and the subscriber for conventional telephone instrument connectivity. A complimentary ADSL interface unit at the subscriber's premises separates downstream video control signals and voice telephone signals from the line and multiplexes upstream control signals and voice telephone signals onto the line. A similar public switched telephone network multimedia information ADSL delivery system is disclosed, for example, in U.S. Pat. No. 5,528,281 to Grady et al.
ADSL offers a wide range of other applications, such as in education, health care, work-at-home access to corporate LANS and interactive services. HDSL has more recently evolved to provide T-1 capability on a normal twisted pair. Implementation may include various bit rates in either direction.
U.S. Pat. No. 5,200,993, issued Apr. 6, 1993 to Wheeler et al., describes a public telephone network distributed imaging system having enhanced capabilities. The distributed imaging system provides centralized image processing to end users and access to a range of image management capabilities residing on a shared platform distributed through a switched telephone system. The shared platform functions as a service bureau in delivering such capabilities to end users.
The distributed imaging system embodies an image platform based on the client-server model with standard communications interfaces to service multiple separate user groups accessing different applications. User groups can supply applications programs which are stored and run on the central hardware in support of respective user requirements. The image server operations are provided as functional primitives. User applications are provided by combining the primitives in a control script.
The provision of myriad services, such as those exemplified above, places a challenge on the ILEC to appropriately correlate usage of its subscribers with the various services offered so that dependable service can be provided and billing accounted therefor. With access to the final link to the subscriber available to CLECs, this challenge is further complicated. An end user may subscribe to various services through a CLEC of its choice, while provision of these subscribed services is conveyed through the plant of an ILEC. The ILEC must be able to determine whether the usage comports with its available capabilities and be able to apply the appropriate billing rates to usage that exceed the standard POTS charges. To further complicate this functionality, services may be distributed among several LECs. For example, the ILEC may continue to provide POTS service to a particular subscriber, while data services may be obtained from a different provider.
Commonly assigned co-pending application Ser. Nos. 08/598,768 and 08/598,772 to Montgomery et. al., both filed Feb. 9, 1996, are directed to utilizing portions of the existing public switched telephone network for alternate purposes, while efficiently and conveniently providing a method of measuring the usage of such circuits for billing purposes. One or more telephone company local loops to subscriber premises may be utilized in whole or in part for providing to such premises a connection to the service platform of a third party alternate service provider. The alternate service provider may be another local telephone company, an interexchange carrier, a video service provider, a multi-media service provider, or the like. The use of the local loop is leased to the third party service provider at a rate dependent upon the usage and nature of usage of the circuit. Information and data to permit efficient and convenient billing for leased usage of such loops is implemented by providing on the local loop a passive monitor. The monitor detects and temporarily stores data relating to the commencement and termination of signaling, the time of day, and the nature of the signaling that occurs. Thus, charges may be dependent not only upon the time duration of signaling, but also on the rate of information transferred. Data collected from the monitors is stored at a monitor center from which it is transferred to a billing operation such as the telephone company Revenue Accounting Office (RAO). The arrangements of these applications are reactive in nature, from the standpoint that communication activity is observed and accounted for so that appropriate billing and any other accounting functionalities can be accurately provided.
The need remains for proactively determining that appropriate service will be provided to subscribers. In the current telephone system it is difficult to determine what kind of transmission is occurring on a particular pair of wires at any given time without physically accessing the wires and measuring activity. With the current system, the ILEC, who unbundles transmission pairs to be used by CLEC customers, cannot realistically sell to the CLEC separate classes of service and be assured that a subscriber to POTS will receive only POTS service and not a higher rated service, for example, ADSL. As ADSL continues to evolve, higher data rates have become available in different classes of ADSL service offerings. Usage higher than that for which the line is subscribed not only would cost the ILEC the difference in billing for over the subscribed class of service, but also may exceed the planned transmission capacities of the ILEC plant.
A related problem exists if an unbundled line is leased to a data services provider for use only for data communication, such as ADSL. The end user would retain POTS service subscription from the ILEC through the separate original line in addition to the newly acquired data service through the leased line. The ILEC should be able to maintain control over the leased line to limit use to the subscribed level of data communication.